Biopsychology Flashcards
1
Q
What is the nervous system?
A
Consists of the central nervous system and the peripheral nervous system.
Communicates using electrical signals.
2
Q
What is the central nervous systen?
A
Consists of the brain and spinal cord and is the origin of all complex commands and decisions.
3
Q
What is the peripheral nervous system?
A
Sends information to the central nervous system from the outside world, and transmits messages from the central nervous system to muscles and glands in the body.
4
Q
What is the somatic nervous system?
A
Transmits information from receptor cells in the sense organs to the central nervous system. It also recieves information from the central nervous system that directs muscles to act.
5
Q
What is the autonomic nervous system?
A
Transmits information to and from internal bodily organs. It is autonomic as the system operates involuntarily.
6
Q
What are the two main divisions of the autonomic nervous system?
A
Sympathetic and parasympathetic.
7
Q
What is the nervous system based on?
A
Electrical and chemical signals.
8
Q
What are the two main functions of the nervous system?
A
- To collect, process and respond to information in the enrivonment.
- To co-ordinate the working of different organs and cells in the body.
9
Q
What is the brain?
A
The centre of all conscious awareness.
10
Q
What is the brain divided into?
A
Two hemispheres.
11
Q
What is the spinal cord?
A
An extension of the brain that passes messages to and from the brain and connects nerves to the peripheral nervous system.
It is also responsible for reflex actions.
12
Q
What does the sympathetic nervous system do?
A
Speeds activity up.
13
Q
What does the parasympathetic nervous system do?
A
Slow activity down.
14
Q
What is the endocrine system?
A
One of the body’s major information systems that instructs glands to release hormones directly into the bloodstream.
These hormones are carried towards target organs in the body.
Communicates via chemicals.
15
Q
What is a gland?
A
An organ in the body that synthesises substances such as hormones.
16
Q
What is a hormone?
A
A biochemical substance that circulates in the blood but only affects target organs. They are produced in large quantities but disappear quickly.
Their effects are very powerful.
17
Q
What is the fight or flight response?
A
The way an animal responds when stressed.
The body becomes physiologically aroused in readiness to fight an aggressor, or in some cases flee.
18
Q
What is adrenaline?
A
A hormone produced by the adrenal medulla which is part of the human body’s immediate stress response system.
Adrenaline has a strong effect on the cells of the cardiovascular system.
19
Q
Name four effects of adrenaline.
A
Sweating
Increased heart rate
Contracting blood vessles
Dilating air passages.
20
Q
How do hormones get into the bloodstream?
A
Secretion.
21
Q
What are the 7 parts of the endocrine system?
A
Hypothalamus
Pituitary gland
Thyroid gland
Adrenal gland
Pancreas
Ovaries (female)
Testes (male)
22
Q
Which two systems work together in a stressful event?
A
Endocrine system and the autonomic nervous system.
23
Q
What happens when a stressor is perceived?
A
The hypothalamus activates the pituitary gland and this triggers activity in the sympathetic branch of the autonomic nervous system.
The autonomic nervous system changes from the parasympathetic state to the sympathetic state.
24
Q
Is the fight or flight response immediate and automatic?
A
Yes
25
What happens once a threat is passed?
The parasympathetic nervous system returns the body to its natural resting state.
26
How is adrenaline released?
The hypothalamus activates the sympathetic branch of the autonomic nervous system through the SAM pathway, ACTH is released from the pituitary gland which then signals the adrenal medulla to secrete adrenaline and noradrenaline.
27
What is a neuron?
The basic building blocks of the nervous system, neurons are nerve cells that process and transmit messages through electrical and chemical signals.
28
What are sensory neurons?
They carry messages from the peripheral nervous system to the central nervous system.
They have long dendrites and short axons.
29
What are relay neurons?
They connect the sensory neurons to the motor or other relay neurons.
They have short dendrites and short axons.
30
What are motor neurons?
They connect the central nervous system to effectors such as muscles or glands.
They have short dendrites and long axons.
31
How do neurons transmit signals?
Electrically or chemically
32
What is the cell body?
Contains a nucleus, which contains the genetic material of the cell.
33
What is a dendron?
Dendrons transmit nerve impulses towards the cell body.
34
What is a dendrite?
The end branches of dendrons which recieve nerve impulses.
35
What is an axon?
An axon carries impulses away from the cell body down the length of the neuron.
36
What is the myelin sheath?
A fatty layer which covers the axon and protects it and speeds up electrical transmission of the impulse.
37
What would happen if the myelin sheath was continuous?
It would have the reverse effect and slow down the electrical impulse.
38
What are nodes of ranvier?
Gaps that segment the myelin sheath amd spped up the transmission of the impulse by forcing it to 'jump' across the gaps along the axon.
39
What are terminal buttons?
The end of the axon are terminal buttons which communicate with the next neuron in the chain across a gap known as the synapse.
40
What are clusters of sensory neurons called?
Ganglia and are found in the PNS.
41
What % of neurons do relay neurons make up?
97% and most are found in the brain.
42
Describe electrical transmission withtin neurons.
- When a neuron is in a resting state, the inside of the cell is negatively charged compared to the outside.
- When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second causing an action potential to occur.
- This creates an electrical impulse that travels down the axon towards the end of the neuron.
43
What is synaptic transmission?
The process by which neighbouring neurons communicate with each other by sending chemical signals across the synapse that separates them.
44
What is a neurotransmitter?
Brain chemicals released from synaptic vesicles that relay signals across the synapse from one neuron to another.
They can be classified as either excitatory or inhibitory.
45
What is excitation?
When a neurotransmitter such as adrenaline, increases the positive charge of the postsynaptic neuron. This increases the likelihood that the postsynaptic neuron will pass on the electrical impulse.
46
What is inhibition?
When a neurotransmitter such as serotonin, increases the negative charge of the postsynaptic neuron. This decreases the likelihood that the postsynaptic neuron will pass on the electrical impulse.
47
What are the groups neurons communicate in called?
Neural networks.
48
What happens when an electrical impulse reaches the presynaptic terminal?
It triggers the release of neurotransmitters from tiny sacs called synaptic vesicles.
49
How do neurotransmitters cross the gap?
Diffusion
50
What happens when neurotransmitters cross the gap?
It is taken up by a postsynaptic receptor site on the dendrites of the next neuron.
Here, the chemical message is converted back into an electrical impulse and the process of transmission begins again in this other neuron.
51
Why can the direction of travel of neurotransmitters be only one-way?
Because neurotransmitters are released from the presynaptic neuron terminal and recieved by the postsynaptic neuron.
52
Does each neurotransmitter have its own specific molecular structure and why?
Yes, this means it will fit perfectly into a postsynaptic receptor site.
53
Name a neurotransmitter and its specific function.
Acetylcholine (ACh) which is found at each point where a motor neuron meets a muscle and upon its release, causes muscles to contract.
54
What process decides whether a postsynaptic neuron fires or not?
Summation.
55
Describe the process of summation.
The excitatory and inhibitory influences are summed; if the net effect on the postsynaptic neuron is inhibitory then the postsynaptic neuron is less likely to fire.
If the net effect on the postsynaptic neuron is excitatory then the postsynaptic neuron is more likely to fire.
Therefore, the action potential of the postsynaptic neuron is only triggered if the sum of the excitatory and inhibitory signals at any one time reaches the threshold.
56
What is localisation of function?
The theory that different areas of the brain are responsible for specific behaviours, processes or activities.
57
What is the motor area?
A region of the frontal lobe involved in regulating movement.
58
What is the somatosensory area?
An area of the parietal lobe that processes sensory information such as touch.
59
What is the visual area?
A part of the occipital lobe that recieves and processes visual information.
60
What is the auditory area?
Located in the temporal lobe and concerned with the analysis of speech-based information.
61
What is Broca's area?
An area of the frontal lobe in the left hemisphere, responsible for speech production.
62
What is Wernicke's area?
An area of the temporal lobe in the left hemisphere, responsible for language comprehension.
63
What are the four lobes of the brain in clockwise order?
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
64
Localisation of function in the brain vs holistic theory.
- In the past scientists supported the holistic theory of the brain which suggested that all parts of the brain were involved in the processing of throught and action.
- Broca and Wernicke argued for localisation of function which means that different parts of the brain perform different tasks and are involved with different parts of the body.
- It follows then, that if a certain area of the brain become damaged through illness or injury, the function associated with that area of the brain will also be affected.
65
Hemispheres of the brain.
- The cerebrum is divided into two symmetrical halves called the left and right hemispheres.
- Some of our physical and psychological functions are controlled or dominated by a particular hemisphere (this is called lateralisation).
- Activity on the left-side of the body is controlled by the right hemisphere and vice versa.
66
What could damage of the motor area mean?
Loss of control over fine movements
67
Where is the motor area?
Back of the frontal lobe, in both hemispheres.
68
Where is the somatosensory area?
Front of both parietal lobes.
69
Where is the visual area?
In the occipital lobe at the bac of tbrain.
70
What could damage to the visual area mean?
Damage to the left hemisphere could produce blindness in part of the right visual field of both eyes.
71
Where is the auditory area?
The temporal lobe.
72
What could damage to the auditory area mean?
Partial hearing loss, the more extensive the damage the more extensive the loss.
73
Where is Broca's area?
Left frontal lobe.
74
What could damage to Broca's area mean?
Broca's aphasia which is characterised by speech that is slow, laborious and lacking in fluency.
75
Where is Wernicke's area?
Left temporal lobe.
76
What could damage to Wernicke's area mean?
Wernicke's aphasia which means the the person will produce nonsense words as part of the content of their speech.
77
Evidence from neurosurgery of localisation of function in the brain.
+ Neurosurgery is a last minute resort for treating some mental disorders, targeting specific areas of the brain which may be involved.
+ For example, cingulotomy involves isolating the cingulate gyrus which has been implicated in OCD.
+ Dougherty et al (2002) reported on 44 people with OCD who had undergone a cingulotomy and at a post-surgical follow up, 30% had met the criteria for successful response and 14% for partial response.
+ Behaviours associated with some mental disorders may be localised.
78
Evidence from brain scans of localisation of function in the brain.
+ Petersen et al (1988) used brain scans to demonstrate how Wernicke's area was active during a listening task and Broca's area was active in a reading task.
+ Buckner and Petersen (1996) revealed that semantic and episodic memories reside in different parts of the prefrontal cortex.
+ Brain scans provide scientific evidence.
- Lashley (1950) removed areas of the cortex in rats that were learning a route through a maze. No area was proven to be more important than any other area in terms of the rats' ability to learn the route.
- Higher cognitive processes, such as learning, may not be localised by distributed in a more holistic way in the brain.
79
Limitation of localisation of function in the brain.
Language may not be localised just to Broca's and Wernicke's areas.
Dick and Tremblay (2016) found that only 2% of modern researchers think that language in the brain is completely controlled by Broca's and Wernicke's areas.
Advances in brain imaging techniques such as fMRI mean that neural processes can be studied with more clarity than ever.
Language function may be distributed more holistically.
So-called language streams have been identified across the cortex, including brain regions in the right hemisphere, as well as subcortical regions such as the thalamus.
Language may be organised more holistically in the brain which contradicts localisation theory.
80
Case study of Phineas Gage.
Gage in 1948, was preparing to remove rock through an explosion.
In the explosion a metre-length pole passed through his left cheek, passing behind his left eye and exiting his skull from the top of his head, taking a portion of his brain with it- most of his left frontal lobe.
He survived that damage but his personality changed from calm to agressive.
Suggests that the frontal lobe may be responsible for regulating mood.
81
Why does the Phineas Gage case study support localisation of function in the brain?
The majority of his brain was still functioning normally and so shows how different areas of the brain have different functions.
82
Case study evidence evaluation for localisation of function.
It is hard to make meaningful generalisations from the findings of a single individual.
Conclusions drawn may depend on the subjective interpretation of the researcher - may not apply to Gage.
83
What is hemispheric lateralisation?
The idea that the two hemispheres of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other.
84
Name a function which is lateralised to both sides of the brain?
Vision
85
Where is language lateralised to and why?
The left hemisphere.
Broca's is in the left frontal lobe and Wernicke's is in the left temporal lobe.
86
What is the right hemisphere's involvement with langauge?
It can only produce rudimentary words and phrases but contributes to the emotional context of what is being said.
87
What are the LH and RH refered to as?
LH= Analyser
RH= Synthesiser
88
Motor and brain lateralisation.
The brain is cross wired.
The RH controls the left side of the body.
The LH controls the right side of the body.
89
Vision and brain lateralisation.
It is contralateral and ipsilateral.
Each eye recieves light from the LVF and RVF.
The LVF of both eyes is connected to the RH and the RVF of both eyes is connected to the LH.
This enables the visual areas to compare the slightly different perspective from each eye and aids depth perception.
90
What is a strength of hemispheric lateralisation?
Research shows that even in connected brains the two hemispheres process information differently.
Fink et ak (1996) used PET scans to identify which brain areas were active during a visual processing task. When participants were asked to attend to the global elements of an image the RH was much more active. The LH tended to dominate when focussing on finer detail.
91
What is a limitation of hemispheric lateralisation?
The idea of LH as analyser and RH as the synthesiser may be wrong.
There may be different functions in the LH and RH but people do not have a dominant side of their brain which creates a different personality.
Nielsen et al. (2013) analysed brain scans from over 1000 people aged 7-29 and did find that people used certain hemispheres for certain tasks but there was no evidence for a dominant side.
92
What does a 'split-brain' operation involve and why is it used?
Severing the connections between the LH and RH, mainly the corpus callosum.
Used to reduce epilepsy.
93
Who investigated split-brains?
Sperry (1968)
94
What was Sperry's (1968) procedure?
11 people who had a split-brain operation were studied using a set up in which an image could be projected to a participant's RVF, and the same, or different, image could be projected to the LVF.
The participant had to stare at a dot in the centre and images were shown for 1/10 of a second.
Presenting the image to one hemisphere of a split-brain participant meant that the information cannot be conveyed from that hemisphere to the other.
95
What is the conclusion of Sperry (1968)?
Certain functions are lateralised in the brain and support the view that the LH is verbal and the RH is 'silent' but emotional.
96
What were the findings of Sperry (1968)?
When a picture of an object was shown to a participant's RVF the participant could describe what was seen. They cound not do this if the object was shown to the LVF.
This is because, in the connected brain, messages from the RH are relayed to language centres in the LH but this is not possible in the split-brain.
Althought participants couldn't give verbal labels to objects projected to the LVF they could select a matching object out of sight using their left hand. The left hand could also select an object that was most closely associated with an object presented to the LVF.
97
What is a strength of split brain research?
Luck et al. 1989 showed that split-brain participants actually perform better than connected controls of certain tasks. For example, they were faster at identifying the odd one out in an array of similar objects than normal controls.
In the normal brain, the LH's better cognitive strategies are 'watered down' by the inferior RH (Kingstone et al. 1995).
This supports Sperry's earlier findings that the 'left brain' and 'right brain' are distinct.
98
What is a limitation of Sperry's split brain research?
Causality is hard to establish.
Sperry's split brain patients were compared to a neurotypical control group an issue of this however was that none of the control participants had epilepsy.
This is a major confounding variable and any differences between the two groups may be a result of epilepsy and not the split brain.
99
What is a possible ethical limitation of Sperry's research?
The procedure was not performed for the purpose of research so his participants were not deliberately harmed.
Full consent was gained and the procedure was fully explained to particiapnts.
However, the trauma of the operation might mean that the participants did not later fuly understand the implications of what they had agreed to. They were subject to repeated testing over lengthy periods and this may have been stressful over time.
100
What is plasticity?
The brain's tendency to change and adapt as a result of experience and new learning.
This generally involves the growth of new connections.
101
What is functional recovery?
A form of plasticity following damage through trauma, the brain's ability to distribute or transfer functions usually performed by a damaged area to other undamaged areas.
102
What is synaptic pruning?
When as we age, rarely used connections are deleted and frequently used connections are strengthened.
103
Name two pieces of research into plasticity.
Maguire et al. (2000)
Draganski et al. (2006)
104
Maguire et al. (2000)
Studied the brains of London taxi drivers and found significantly more grey matter in the posterior hippocampus than in a matched control group.
London cab drivers must complete a test called the knowledge when they start the job.
The longer people had been taxi drivers, the more pronounced was the structural difference (positive correlation).
105
Draganski et al. (2006)
Imaged the brain of medical students three months before and after their exams.
Learning-induced changes were seen to have occurred in the posterior hippocampus and the parietal cortex presumably as a result of the training.
106
What are axonal sprouting, denervation supersensitivity and recrutiment of homologous areas on the opposite side of the brain?
Structural changes in the brain
107
What is axonal sprouting?
The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways.
108
What is denervation supersensitivity?
Occurs when axons that do a similar job become aroused to a higher level to compensate for the ones which are lost.
However, it can have the negative consequence of oversensitivity to messages such as pain.
109
What is recruitment of homologous areas on the opposite sides of the brain?
It means specific tasks can still be performed.
For example, if Broca's areas was damaged on the left side of the brain, the right-sided equivalent would carry out its function.
After a period of time, functionality may then shift back to the left side.
110
What is a strength of plasticity?
It may be a life-long ability.
Bezzola et al. (2012) demonstrated how 40 hours of golf training produced changes in the neural representations of movement in participants aged 40-60.
Using fMRI, the researchers observed reduced motor cortex activity in the novice golfers compared to a control group, suggesting more efficient neural representations after training.
111
What is a limitation of plasticity?
It may have negative behavioural consequences.
Medina et al. (2007) has found that the brain's adaption to prolonged drug use leads to poorer cognitive functioning later on in life, as well as increased risk of dementia.
This suggests that the brain's ability to adapt to damage is not always beneficial.
112
What is a strength of functional recovery?
Real world application.
Understanding the processes involved in plasticity has contributed to the field of neurorehabilitation.
Simply understanding that axonal growth is possible encourages new therapies to be tried for example constraint-induced movement therapy.
113
What is a weakness of functional recovery?
Level of education may influence recovery rates.
Schneider et al. (2014) revealed that the more time people with a brain injury spent in education, the greater their chances of disability-free recovery.
40% of those with 16 years of education or more achieved DFR.
